The joy of ... Qtractor with synth plugins

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bluebell
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The joy of ... Qtractor with synth plugins

Post by bluebell »

Hi all,

I fiddled around a lot with Qtractor. I need:
- lots of tracks with synth plugins (including one track per drum to pan and reverb it individually)
- audio tracks with vocals

So I thought to pan and level and enrich a synth track (midi track with synth plugin) I would have to create a connected audio bus where I do the aux/insert send correctly (post fade only works in the output part, right side).

That's not true. There is a much simpler way.

- create an output bus, use your favourite reverb, e.g. KlangFalter, dry level 0, wet level full
- create a midi track with a synth module, e.g. fluidsynth
- insert in that track:
1.) LADSPA stereo amplifier, set direct access to "gain". This will become your volume fader.
2.) C*Pan, set direct access to "pan". This will become your pan knob.
3.) Aux send to the reverb output bus, set direct access to "send gain". This is your first effect send. Post fader! Hooray!

Et voilà, you won't end up in a mess with lots of audio busses AND it avoids some problems with audio routing from one bus' output to another bus' input when the receiving bus has been created after the sending one. That sequence can be fixed with a text editor in the session file but it's fine if you don't need it.

Another advantage is the possibility to automate every audio level and send(!) in the midi track. I don't know if its possible to automate parms that are in audio busses but not in tracks.

I am looking forward to the next time I start a new song. Qtractor is a fine piece of software. Kudos to Rui.

I think this will help me a lot.
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

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bluebell
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Re: The joy of ... Qtractor with synth plugins

Post by bluebell »

I made a patch to make the mixer strips a bit wider and the plugins-box higher:

Code: Select all

--- ./src/qtractorMixer.cpp.orig	2013-12-01 12:47:01.014117834 +0100
+++ ./src/qtractorMixer.cpp	2013-12-01 12:45:44.503061837 +0100
@@ -297,7 +297,7 @@
 
 	m_pPluginListView = new qtractorPluginListView(/*this*/);
 	m_pPluginListView->setFont(font2);
-	m_pPluginListView->setFixedHeight(iFixedHeight << 2);
+	m_pPluginListView->setFixedHeight(iFixedHeight << 3); /* -hm- instead of << 2*/
 	m_pPluginListView->setTinyScrollBar(true);
 	m_pLayout->addWidget(m_pPluginListView);
 
@@ -366,7 +366,7 @@
 	// Now, there's whether we are Audio or MIDI related...
 	m_pMeter = NULL;
 	m_pMidiLabel = NULL;
-	int iFixedWidth = 42;
+	int iFixedWidth = 52; /* -hm- instead of 42 */
 	switch (meterType) {
 	case qtractorTrack::Audio: {
 		// Type cast for proper audio monitor...
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

varpa
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Re: The joy of ... Qtractor with synth plugins

Post by varpa »

Thanks for your tutorial which I tried and learned something new about qtractor. One thing that I found strange is that the reverb bus output sent to the system out by default, whereas I would prefer to send it to the master bus to have control over the final output. Seemingly one could connect the reverb output to the master bus using the Connections panel, but this did not actually send the reverb sound to the master bus. So the solution was to make an aux send from the reverb bus to the master bus, or by putting the reverb directly on the master bus and not using a reverb bus at all. I do not understand why the amplifier plugin is needed, seems like you can just use the channel fader, though maybe that operates on midi velocities rather than audio output. I did not seem to have the C*pan plugin available, and I could not find another panner that worked. Another feature of Qtractor I find not ideal is that the mixer panel cannot be viewed independently of the main panel. In fact in kxstudio, the mixer panel would only appear if the main panel is the active panel (?) which was highly annoying. In AVlinux the mixer panel will at least stay visible when the main panel does not have the focus.

I have to say I find this sort of set up is easier in Ardour3 (bus setup more straightforward, midi channel panner works directly), but its good to have options.

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bluebell
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Re: The joy of ... Qtractor with synth plugins

Post by bluebell »

I uncheck "Auto connect" and connect the reverb bus manually to "Master in". Qtractor remembers this.
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

varpa
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Re: The joy of ... Qtractor with synth plugins

Post by varpa »

After more experimentation I see that qtractor could be set up reasonably well for live play as an instrument host. One can make various midi tracks containing synths or linuxsampler, etc and control which instruments play using the the monitor button on each track to control whether the sound is heard or not (seems to control sending of the midi signal to the synth, which is good because if you are not playing the instrument then no disk reads or CPU should be needed by the track). I see that the channel pan control does work so I do not see the need for a pan plugin. One can insert whatever plugins are wanted for each track and turn them on an off as needed. I've been using Ardour3 as virtual instrument host and I see qtractor work basically just as well.

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rncbc
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Re: The joy of ... Qtractor with synth plugins

Post by rncbc »

varpa wrote:[...] Another feature of Qtractor I find not ideal is that the mixer panel cannot be viewed independently of the main panel. In fact in kxstudio, the mixer panel would only appear if the main panel is the active panel (?) which was highly annoying. In AVlinux the mixer panel will at least stay visible when the main panel does not have the focus.
maybe View/Options.../General/Keep tool windows always on top option will help if turned off?

cheers
Last edited by rncbc on Mon Dec 02, 2013 3:35 pm, edited 5 times in total.

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bluebell
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Re: The joy of ... Qtractor with synth plugins

Post by bluebell »

varpa wrote:I do not understand why the amplifier plugin is needed, seems like you can just use the channel fader, though maybe that operates on midi velocities rather than audio output. I did not seem to have the C*pan plugin available, and I could not find another panner that worked.
The fader and panner of a midi track affect midi processing. That doesn't always work as desired, depending on the synth plugin and its settings. That's the reason why I use

- "C* Pan (Pan and width)" in package "caps" on my Xubuntu 12.04 LTS
- "Stereo Amplifier" in package "ladspa-sdk" on my Xubuntu 12.04 LTS
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

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rncbc
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Re: The joy of ... Qtractor with synth plugins

Post by rncbc »

varpa wrote:Another feature of Qtractor I find not ideal is that the mixer panel cannot be viewed independently of the main panel. In fact in kxstudio, the mixer panel would only appear if the main panel is the active panel (?) which was highly annoying. In AVlinux the mixer panel will at least stay visible when the main panel does not have the focus.
alas, ootb. KDE (thus kxstudio i presume) has this default setting of hiding special tool windows when their main application window loses focus; can't quite remember precisely where in desktop settings , i guess somewher under some "advanced" tab on "window behavior" ... sth.like that...

hth.
cheers

varpa
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Re: The joy of ... Qtractor with synth plugins

Post by varpa »

rncbc: Thanks for the tip - I was able to fix the disappearing mixer panel as follows:
System settings -> Window behavior -> Window behavior -> Advanced tab
-> un-Click box at bottom: "Hide utility windows for inactive applications"

SR
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Re: The joy of ... Qtractor with synth plugins

Post by SR »

varpa wrote:rncbc: Thanks for the tip - I was able to fix the disappearing mixer panel as follows:
System settings -> Window behavior -> Window behavior -> Advanced tab
-> un-Click box at bottom: "Hide utility windows for inactive applications"
I can't tell you how long this has been bugging me. I love KDE but its default settings are mind bogglingly dumb.

JollyBard
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Re: The joy of ... Qtractor with synth plugins

Post by JollyBard »

varpa wrote:After more experimentation I see that qtractor could be set up reasonably well for live play as an instrument host. One can make various midi tracks containing synths or linuxsampler, etc and control which instruments play using the the monitor button on each track to control whether the sound is heard or not (seems to control sending of the midi signal to the synth, which is good because if you are not playing the instrument then no disk reads or CPU should be needed by the track). I see that the channel pan control does work so I do not see the need for a pan plugin. One can insert whatever plugins are wanted for each track and turn them on an off as needed. I've been using Ardour3 as virtual instrument host and I see qtractor work basically just as well.
I've been using Qtractor in live performances and this is exactly how went about it. I assigned buttons on my controller to the monitors of each track and so I was able to switch between each instrument, or, if I had wanted, play multiple instruments at the same time. The only problem was that sometimes I would forget to release all keys before switching and a note would be played continuously until I distraughtedly pressed the panic! button.

I used it with Windows VSTs with FalkTX's dssi-vst, so it was kind of unstable, but I think Qtractor itself is usually stable enough for live shows.

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rncbc
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Re: The joy of ... Qtractor with synth plugins

Post by rncbc »

JollyBard wrote:
varpa wrote:After more experimentation I see that qtractor could be set up reasonably well for live play as an instrument host. One can m
    ake various midi tracks containing synths or linuxsampler, etc and control which instruments play using the the monitor button on each track to control whether the sound is heard or not (seems to control sending of the midi signal to the synth, which is good because if you are not playing the instrument then no disk reads or CPU should be needed by the track). I see that the channel pan control does work so I do not see the need for a pan plugin. One can insert whatever plugins are wanted for each track and turn them on an off as needed. I've been using Ardour3 as virtual instrument host and I see qtractor work basically just as well.
    I've been using Qtractor in live performances and this is exactly how went about it. I assigned buttons on my controller to the monitors of each track and so I was able to switch between each instrument, or, if I had wanted, play multiple instruments at the same time. The only problem was that sometimes I would forget to release all keys before switching and a note would be played continuously until I distraughtedly pressed the panic! button.

    I used it with Windows VSTs with FalkTX's dssi-vst, so it was kind of unstable, but I think Qtractor itself is usually stable enough for live shows.
    there's also and always this Track/Auto Monitor option which applies to the current highlighted track.

    you might find it handy, in the context of live redirecting one MIDI keyboard controller input through realtime audition of instrument plugins. Also, MIDI track/channel filtering is done automagically there ;)

    hth.
    cheers

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    sysrqer
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    Re: The joy of ... Qtractor with synth plugins

    Post by sysrqer »

    bluebell wrote:I made a patch to make the mixer strips a bit wider and the plugins-box higher:

    Code: Select all

    --- ./src/qtractorMixer.cpp.orig	2013-12-01 12:47:01.014117834 +0100
    +++ ./src/qtractorMixer.cpp	2013-12-01 12:45:44.503061837 +0100
    @@ -297,7 +297,7 @@
     
     	m_pPluginListView = new qtractorPluginListView(/*this*/);
     	m_pPluginListView->setFont(font2);
    -	m_pPluginListView->setFixedHeight(iFixedHeight << 2);
    +	m_pPluginListView->setFixedHeight(iFixedHeight << 3); /* -hm- instead of << 2*/
     	m_pPluginListView->setTinyScrollBar(true);
     	m_pLayout->addWidget(m_pPluginListView);
     
    @@ -366,7 +366,7 @@
     	// Now, there's whether we are Audio or MIDI related...
     	m_pMeter = NULL;
     	m_pMidiLabel = NULL;
    -	int iFixedWidth = 42;
    +	int iFixedWidth = 52; /* -hm- instead of 42 */
     	switch (meterType) {
     	case qtractorTrack::Audio: {
     		// Type cast for proper audio monitor...
    
    What do I need to do with this if I want to apply?

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    rncbc
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    Re: The joy of ... Qtractor with synth plugins

    Post by rncbc »

    sysrqer wrote:
    bluebell wrote:I made a patch to make the mixer strips a bit wider and the plugins-box higher:

    Code: Select all

    --- ./src/qtractorMixer.cpp.orig	2013-12-01 12:47:01.014117834 +0100
    +++ ./src/qtractorMixer.cpp	2013-12-01 12:45:44.503061837 +0100
    @@ -297,7 +297,7 @@
     
     	m_pPluginListView = new qtractorPluginListView(/*this*/);
     	m_pPluginListView->setFont(font2);
    -	m_pPluginListView->setFixedHeight(iFixedHeight << 2);
    +	m_pPluginListView->setFixedHeight(iFixedHeight << 3); /* -hm- instead of << 2*/
     	m_pPluginListView->setTinyScrollBar(true);
     	m_pLayout->addWidget(m_pPluginListView);
     
    @@ -366,7 +366,7 @@
     	// Now, there's whether we are Audio or MIDI related...
     	m_pMeter = NULL;
     	m_pMidiLabel = NULL;
    -	int iFixedWidth = 42;
    +	int iFixedWidth = 52; /* -hm- instead of 42 */
     	switch (meterType) {
     	case qtractorTrack::Audio: {
     		// Type cast for proper audio monitor...
    
    What do I need to do with this if I want to apply?
    > patch -p0

    while on qtractor source tree...a simple exercise on the greater joys of open-source world ;)

    cheers

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